In radiographic examinations, particularly in pulmonary examinations, “Ground glass nodules” (GGNs) generally refer to radiographic appearances of hazy lung opacities not associated with an obscuration of underlying vessels. GGNs are typically found in two forms, “pure” and “mixed”. Pure GGNs do not include solid components, whereas mixed GGNs include some solid components.
GGNs are more clearly shown in high resolution computed tomographic (HRCT) images than in plain radiographs. GGNs typically also exhibit a different appearance from solid nodules in HRCT images because solid nodules have a higher contrast and well defined boundaries. In addition, the appearance of GGNs in HRCT images is a highly significant finding as they often indicate the presence of an active and potentially treatable process such as bronchiolalveolar carcinomas or invasive adenocarcinoma.
Because GGNs are typically associated with active lung disease, the presence of GGNs often leads to further diagnostic evaluation, including, for example, lung biopsy. Thus, a computer-based segmentation can be of assistance to medical experts for diagnosis and treatment of certain types of lung disease. Accordingly, there is a need for a system and method of computer-based segmentation that can be used to accurately and consistently segment GGNs for quick diagnosis.